instrument gauges messing up

[blh0007]

any time i turn on the a/c blower, windshield wipers, blinker, lights, hit the brakes...anything electrical the instrument gauges start goofing up. to be specific the oil pressure gauge goes up. the temp gauge goes up and the battery gauge goes down. guy at the ford place told me it sounds like i'm having a ground issue. any ideas as to why.thanks

 

[tedrisch]

All those tie to Ground 103.

Driver side fenderwell, closest ground point to the hinge, IIRC.

Clean that up.